Daily report · most polluted
Thailand air quality on 18 October 2026
Kanchanaburi Kanchanaburi100
ModerateUS AQI
Kanchanaburi had the most polluted air of 59 Thai cities
Updated · PCD
At 3:00 pm ICT on 18 October 2026, 59 Thai cities were reporting. Kanchanaburi had the most polluted air at US AQI 100 (Moderate), followed by Nong Khai (82) and Maha Sarakham (80). The median across all cities was 63, down from 66 the day before. 0 cities were at Unhealthy or worse (0 the day before). Sa Kaeo had the cleanest air at 47.
The biggest deterioration was in Phichit, from 50 to 69. Narathiwat improved most, from 87 to 64.
- Good 2
- Moderate 57
10 most polluted cities
| # | City | Province | US AQI | Change |
|---|---|---|---|---|
| 1 | Kanchanaburi | Kanchanaburi | 100Moderate | ▼ 9 |
| 2 | Nong Khai | Nong Khai | 82Moderate | ▲ 8 |
| 3 | Maha Sarakham | Maha Sarakham | 80Moderate | ▲ 7 |
| 4 | Nakhon Ratchasima | Nakhon Ratchasima | 80Moderate | ▲ 2 |
| 5 | Roi Et | Roi Et | 75Moderate | ▼ 2 |
| 6 | Chiang Rai | Chiang Rai | 74Moderate | ▲ 2 |
| 7 | Khon Kaen | Khon Kaen | 74Moderate | ▼ 4 |
| 8 | Udon Thani | Udon Thani | 74Moderate | ▲ 8 |
| 9 | Bangkok | Bangkok | 72Moderate | ▲ 3 |
| 10 | Lopburi | Lopburi | 71Moderate | ▲ 16 |
10 cleanest cities
| # | City | Province | US AQI | Change |
|---|---|---|---|---|
| 1 | Sa Kaeo | Sa Kaeo | 47Good | ▼ 5 |
| 2 | Chanthaburi | Chanthaburi | 49Good | ▼ 2 |
| 3 | Krabi | Krabi | 52Moderate | ▼ 11 |
| 4 | Chumphon | Chumphon | 52Moderate | ▼ 7 |
| 5 | Trang | Trang | 53Moderate | ▼ 18 |
| 6 | Phatthalung | Phatthalung | 53Moderate | ▼ 19 |
| 7 | Mae Hong Son | Mae Hong Son | 53Moderate | ▲ 2 |
| 8 | Nakhon Nayok | Nakhon Nayok | 54Moderate | ▼ 3 |
| 9 | Trat | Trat | 56Moderate | ▲ 1 |
| 10 | Nong Bua Lamphu | Nong Bua Lamphu | 56Moderate | ▼ 3 |
Biggest rises
All 59 cities on 18 October 2026
| # | City | Province | US AQI | Change |
|---|---|---|---|---|
| 1 | Kanchanaburi | Kanchanaburi | 100Moderate | ▼ 9 |
| 2 | Nong Khai | Nong Khai | 82Moderate | ▲ 8 |
| 3 | Maha Sarakham | Maha Sarakham | 80Moderate | ▲ 7 |
| 4 | Nakhon Ratchasima | Nakhon Ratchasima | 80Moderate | ▲ 2 |
| 5 | Roi Et | Roi Et | 75Moderate | ▼ 2 |
| 6 | Chiang Rai | Chiang Rai | 74Moderate | ▲ 2 |
| 7 | Khon Kaen | Khon Kaen | 74Moderate | ▼ 4 |
| 8 | Udon Thani | Udon Thani | 74Moderate | ▲ 8 |
| 9 | Bangkok | Bangkok | 72Moderate | ▲ 3 |
| 10 | Lopburi | Lopburi | 71Moderate | ▲ 16 |
| 11 | Rayong | Rayong | 71Moderate | 0 |
| 12 | Pathum Thani | Pathum Thani | 70Moderate | ▲ 5 |
| 13 | Phichit | Phichit | 69Moderate | ▲ 19 |
| 14 | Buriram | Buriram | 68Moderate | ▼ 6 |
| 15 | Chai Nat | Chai Nat | 68Moderate | ▲ 8 |
| 16 | Kalasin | Kalasin | 68Moderate | ▼ 3 |
| 17 | Chiang Mai | Chiang Mai | 66Moderate | ▲ 3 |
| 18 | Suphun Buri | Suphun Buri | 66Moderate | ▲ 13 |
| 19 | Amnat Charoen | Amnat Charoen | 65Moderate | ▼ 2 |
| 20 | Loei | Loei | 65Moderate | ▲ 2 |
| 21 | Saraburi | Saraburi | 65Moderate | ▲ 6 |
| 22 | Yasothon | Yasothon | 65Moderate | ▼ 4 |
| 23 | Chaiyaphum | Chaiyaphum | 64Moderate | ▼ 3 |
| 24 | Mukdahan | Mukdahan | 64Moderate | ▼ 3 |
| 25 | Nakhon Phanom | Nakhon Phanom | 64Moderate | ▼ 4 |
| 26 | Narathiwat | Narathiwat | 64Moderate | ▼ 23 |
| 27 | Phayao | Phayao | 64Moderate | ▲ 4 |
| 28 | Prachuap Khiri Khan | Prachuap Khiri Khan | 64Moderate | ▼ 13 |
| 29 | Ratchaburi | Ratchaburi | 64Moderate | ▼ 2 |
| 30 | Phrae | Phrae | 63Moderate | ▲ 3 |
| 31 | Prachin Buri | Prachin Buri | 63Moderate | 0 |
| 32 | Sukhothai | Sukhothai | 63Moderate | ▲ 6 |
| 33 | Lampang | Lampang | 62Moderate | ▲ 4 |
| 34 | Pattanee | Pattanee | 62Moderate | ▼ 21 |
| 35 | Chachoengsao | Chachoengsao | 61Moderate | ▲ 2 |
| 36 | Nakhon Sawan | Nakhon Sawan | 61Moderate | ▲ 3 |
| 37 | Sakon Nakhon | Sakon Nakhon | 61Moderate | ▲ 3 |
| 38 | Sisaket | Sisaket | 61Moderate | ▼ 8 |
| 39 | Songkhla | Songkhla | 61Moderate | ▼ 23 |
| 40 | Ubon Ratchathani | Ubon Ratchathani | 61Moderate | ▼ 3 |
| 41 | Chon buri | Chon buri | 60Moderate | ▼ 4 |
| 42 | Kamphaeng Phet | Kamphaeng Phet | 60Moderate | 0 |
| 43 | Phetchabun | Phetchabun | 59Moderate | ▼ 1 |
| 44 | Surin | Surin | 59Moderate | ▼ 10 |
| 45 | Bueng Kan | Bueng Kan | 58Moderate | 0 |
| 46 | Nakhon Si Thammarat | Nakhon Si Thammarat | 58Moderate | ▼ 20 |
| 47 | Phuket | Phuket | 58Moderate | ▼ 19 |
| 48 | Satun | Satun | 58Moderate | ▼ 19 |
| 49 | Surat Thani | Surat Thani | 57Moderate | ▼ 20 |
| 50 | Nong Bua Lamphu | Nong Bua Lamphu | 56Moderate | ▼ 3 |
| 51 | Trat | Trat | 56Moderate | ▲ 1 |
| 52 | Nakhon Nayok | Nakhon Nayok | 54Moderate | ▼ 3 |
| 53 | Mae Hong Son | Mae Hong Son | 53Moderate | ▲ 2 |
| 54 | Phatthalung | Phatthalung | 53Moderate | ▼ 19 |
| 55 | Trang | Trang | 53Moderate | ▼ 18 |
| 56 | Chumphon | Chumphon | 52Moderate | ▼ 7 |
| 57 | Krabi | Krabi | 52Moderate | ▼ 11 |
| 58 | Chanthaburi | Chanthaburi | 49Good | ▼ 2 |
| 59 | Sa Kaeo | Sa Kaeo | 47Good | ▼ 5 |
Snapshot taken at 3:00 pm ICT from Pollution Control Department (PCD) · Air4Thai. Values are the latest hourly readings at that time, not daily averages. Cities with no reading are left out.